Liquid crystal display devices include a liquid crystal layer disposed between two substrates and provide light and dark images by using the electro-optical response of the liquid crystal layer, while the display devices can display color images by using a color filter substrate.
Conventionally, the predominant black matrices formed in color filter substrate have been thin metal films of a chromium material, while resin black matrices that include a resin and a light-shielding material have been developed for reducing costs and environmental pollution.
However, although liquid crystal display devices including a color filter substrate, on which a resin black matrix containing a light-shielding material such as carbon black was formed, exhibit good visibility in indoor environments, the devices have the problem of reduced visibility in outdoor environments due to reflection of external light caused by the resin black matrix.
In view of the foregoing, various investigations have been carried out to provide a resin black matrix having a high optical density and a low reflectance from the back side surface of the substrate. For example, a method of using black colorant particles having a surface coated with an insulating material (Patent Document 1), a method of adding carbon black to titanium nitride oxide (Patent Document 2), a method of mixing titanium nitride with titanium carbide (Patent Document 3), a method of providing a two-layered structure of a color relief layer and a black relief layer (Patent Document 4), and a method of providing a two-layered structure of a light absorbing layer that contains shape-anisotropic metal particles and a reflected-light absorbing layer (Patent Document 5) have been proposed.